Docking unit for portable computer

ABSTRACT

According to the present invention, provided is a superior docking unit for a portable computer that can provide adequate theft prevention environments for a “single user mode” during which the docking unit is used by only one user, and a “multi-user mode” during which the docking unit is shared by a plurality of users. A docking unit for a portable computer according to the present invention has first and second kensington slots positioned on the outer wall of the main body. When the kensington lock is inserted into the first kensington slot, this event is transmitted to inhibit the release of the engagement of the mounted portable computer, to enable its removal and to restrict the exchange of a PC card relative to the docking unit. But when the kensington lock is inserted into the second kensington slot, this event is not transmitted, so that the mounted portable computer can be removed, and restriction for the exchange of the PC card relative to the docking unit is released. Therefore, in the single user mode, the first kensington lock shall be inserted into the first kensington slot, so that the portable computer and the docking unit can be secured together. In the multi-user mode, the kensington lock shall be inserted into the second kensington slot, so that only the docking unit is secured, the attachment/removal of the portable computer is ensured, and the exchange of the PC card is enabled.

This is a division of application Serial No. 08/995,722, filed Dec. 22,1997 now U.S. Pat. No. 6,570,758.

FIELD OF THE INVENTION

The present invention relates to a docking unit for a portable computeron which is mounted a portable computer to expand its various functions,and in particular, relates to a docking unit for a portable computerthat can adequately prevent the main body of the docking unit and aportable computer mounted thereon from being stolen. More specifically,the present invention pertains to a docking unit for a portable computerthat provides an adequate security function relative to the environmentsin which it is used, in a “single user mode,” during which the dockingunit is employed by only one user, and in a “multi-user mode,” duringwhich the docking unit is shared by a plurality of users.

DESCRIPTION OF THE BACKGROUND

As a consequence of recent technical developments, various types ofpersonal computers (PC), such as desktop, tower and notebook types, arebeing manufactured and sold. Generally, desktop and tower computers aredesigned to be used on desks or tables in offices and in homes; whereasnotebook computers, for which portability is a design consideration, aredesigned to be operated by batteries in a mobile environment.

Notebook PC and Docking Station

Since it is important that a notebook PC be light and compact, insideone there is no extra space for the installation of expansion adaptorcards and peripheral devices. Further, relying on only a PC card toprovide for the expansion of the periphery of a notebook PC isinadequate. And although portability is an important feature of notebookPCs, it is often necessary for a cable (a printer cable, a monitorcable, or a communication cable) to be connected to and disconnectedfrom a notebook computer between office use and mobile use, so that itsemployment involves some very complicated work and its usability isdeteriorated.

A “docking station” (also called an “expansion box” or an “expansionunit”) provides for a notebook computer the same work environment asthat provided by a desktop or a tower PC when the notebook computer isto be used in an office, while at the same time not deteriorating fromthe portability of the notebook PC. The main functions of the dockingstation are two: “port replication” and “bus expansion.” A portreplication is implemented by providing connection ports for a notebookPC on the docking station. That is, if peripheral devices are connectedin advance to the ports on the docking station, a user need only mounthis or her notebook PC on the docking station and immediately can use aprinter, an external monitor, an external keyboard and a network. When auser desires to transport a notebook PC, he or she need simply remove itfrom the docking station, leaving all the cables connected to thedocking station. Since the port replication function of the dockingstation collectively manages the cable connections, this function isalso called a “cable management function.” The bus expansion function isimplemented by the docking station expanding an input/output bus (or thelocal bus) of the notebook PC or by providing a bus slot on the dockingstation. In other words, while an expansion adaptor card or peripheraldevices can not be attached to the notebook PC, these devices can beused through the docking station. A docking station that provides onlyport replication may be called a “port replicator”.

In FIG. 11 is shown a typically styled notebook PC 100 and a dockingstation 200. The notebook PC 100 has a docking connector (not shown) onits rear face. The docking connector normally includes several tens toseveral hundreds of connector pins. Each connector pin is allocated fora port signal or a bus signal transmitted by the notebook PC 100.

The docking station 200 comprises a relatively thick main body in whichelectric circuits are incorporated, with thin mounting portion by whichthe notebook PC 100 is mounted at the front of the main body. Aconnector, 101, for joining the docking connector (previously described)to the rear face of the notebook PC 100 is provided at the front of themain body. A cover that can be opened and closed may be provided on thesurface of the docking connector to protect it from a mechanical impactwhen the docking station is not used. A pair of linear protrusions, 102and 103, along which the notebook PC 100 is guided in the attachmentdirection, may be formed on either side edge of the mounting portion.

The functions and the structure of a docking station are alreadydisclosed in Japanese Patent Applications No. Hei 05-181593 (U.S. Ser.No. 08/276,231, filed Jul. 18, 1994 and now abandoned) and No. Hei06-134124 (U.S. Ser. No. 08/416,398 filed Apr. 6, 1995), both of whichwere assigned to the present assignee.

The employment styles for the docking station can be classified as a“single user mode” and a “multi-user mode.” In the single user mode,only one PC user employs the docking station. In other words, only onespecific notebook PC is mounted on a docking station. In the multi-usermode, a plurality of PC users employ the docking station in common. Inthe multi-user mode, therefore, the notebook PCs of a number ofindividual users may alternately be mounted on one docking station.

Security of Notebook PC

While various electronic apparatuses are made compact and light and thusare easy to carry, an unwanted side effect of this is that thefts of theapparatuses have increased. Notebook PCs especially tend to be stolenbecause their processing capability has been improved and also becausenotebook PCs have become popular. Peripheral devices that are detachablyconnected to a PC may also be stolen. For example, since a PC card is acartridge type and is only as small as a business card, it can easily bestolen. A removable hard disk drive, HDD, may also be stolen because ofthe data it holds. Therefore, today, the emphasis is on improving officesecurity, i.e., instituting countermeasures to prevent the theft ofelectronic apparatuses.

The theft of a notebook PC can be easily prevented by employing aso-called “kensington lock.” The kensington lock, 105 and 107, is usedto inhibit the removal of a notebook PC from a predetermined location byone end of the lock's main body being fixed to an external wall of thecase of the notebook PC (e.g., in FIG. 12, the side of the case shown in(a) or the rear face in (b)), and by securing the cable that extendsfrom the lock's main body at a specific location in an office (e.g., theleg of a desk). The kensington lock is an optional component that issold separately from the notebook PC. A kensington lock sold byKensington Microware Limited can be employed.

FIG. 13 is a schematic diagram illustrating the assembly of thekensington lock. The kensington lock is constituted by a housing whereina spindle is rotatably provided.

The spindle has a first portion retained in the housing, and a T-shapedshaft that is fixed to the first portion and projects outward from thehousing. The length of the leg of the T-shaped shaft, which projectsoutward from the housing, almost equals the thickness of the externalwall of the case of the notebook PC (see FIGS. 14(a) and 15(a)). Theouter size of the head of the T-shaped shaft almost equals the innerdimensions of a kensington slot formed in the external wall of thenotebook PC (see FIGS. 13(c) and (d), and FIG. 14(b)). A pair of raisedcontact members are formed at the end of the housing to sandwich the legof the shaft. The size in cross section of an assembly of the pair ofcontact members and the leg of the T-shaped shaft almost equals theinner dimensions of the kensington slot formed in the external wall ofthe notebook PC (see FIGS. 13(c) and (e)). The kensington lock can beinserted into the kensington slot at the shaft rotation position wherethe head of the T-shaped shaft overlaps the contact members.

A key hole (not shown in FIG. 13) is formed in the other end (thereverse face of the housing) of the spindle. A key that has engaged thekey hole can be rotated, together with the spindle, i.e, the T-shapedshaft, through an angle of 90°. Therefore, by superimposing the head ofthe T-shaped shaft on the outline of the contact members, this assemblycan be inserted into the kensington slot (see FIGS. 14(a) and 14(b)).After the kensington lock is inserted into the kensington slot, the key,116, fitted in the key hole is rotated 90° to inhibit removal of thekensington lock from the kensington slot (see FIGS. 15(a) and 15(b)). Inthis condition, the key is extracted from the key hole, so that thespindle, i.e., the T-shaped shaft can not be rotated, and the kensingtonlock is secured to the external wall of the PC. A tab accepting one endof a cable, 114, is provided on the side of the housing. The other endof the cable (not shown) is secured at a specified location in an office(e.g., to the leg of a desk), so that the PC to which the kensingtonlock is attached can not be carried away.

The details of the kensington lock are also disclosed in U.S. Pat. No.5,381,685 (Japanese Unexamined Patent Publication No. Hei 06-511297).

Security of Docking Station

There are two primary purposes of providing security for the dockingstation. The first purpose is the security of the docking stationitself, and the second purpose is the security of a notebook PC mountedon the docking station. For the first purpose, security can be easilyimplemented by securing the kensington lock to the main body of thedocking station, as well as to the main body of the notebook PC.

For the second purpose, security is not so easily achieved because thedocking station has two different use styles, the single user mode andthe multi-user mode, and the applicable security policy differs for eachmode. In the single user mode, the security for both the docking stationand the mounted notebook PC is required, and both apparatuses should besecured at a predetermined location in the office. In the multi-usermode, although the docking station has to be secured at a predeterminedlocation in the office, a notebook PC should not be secured to thedocking station, else shared use of the docking station by other useswould not be possible.

A port replicator (Product Model ID No. 46H4219), which is designed andproduced by IBM Corp. for the notebook computer “IBM ThinkPad560(“ThinkPad” is a trademark of IBM Corp.) sold by IBM Japan, Ltd.,interacts with the insertion of the kensington lock into the kensingtonslot and restricts the operation of the ejection mechanism for thenotebook PC. In short, the notebook PC and the port replicator areintegrally locked. The security mechanism is specifically designed foruse in a single user mode.

Docking station “Dock,/SelectaDock,” which is designed and produced byIBM Corp. for the notebook PC “IBM ThinkPad760” sold by IBM Japan, Ltd.,includes a kensington slot for securing the docking station, and a PClocking mechanism for securing a notebook PC to the docking station. Thekensington lock and the PC locking mechanism can be operated byindividual keys, and the locking mechanism does not interact with theattachment of the kensington lock. In this case, since a user canseparately select the use for the kensington lock and the locking of thenotebook PC, a difference between the security policies for the singleuser mode and the multi-user mode can be absorbed. However, a user mustbe accountable for two different keys and bear more responsibility forsecurity.

In Japanese Unexamined Patent Publications No. Hei 06-124141 and No. Hei07-104884, prevention of the theft of an expansion unit is the statedpurpose and a technique for locking a notebook PC to the expansion unitis disclosed. These publications merely provide for the notebook PC tobe secured to the expansion unit for stable employment, and do not takeinto consideration the use of the expansion unit when switching betweenthe single user mode and the multi-user mode is performed.

Recently, as was previously described, a notebook PC and a dockingstation have a PC card slot for inserting a PC card. Since plug-and-playis the standard specification for the PC card, a cartridge form factoris used with which attachment and removal is easy, and accordingly, PCcard theft is easy. The prevention of PC card theft from a notebook PCis recited in, for example, Japanese Patent Application No. Hei05-182972 (Japanese Unexamined Patent Publication No. Hei 07-44269: ourdocket No. JA9-93-030), which was assigned to the present inventor.According to this specification, a curved engagement piece is attachednear a PC card exchange opening in the PC main body to prevent theremoval of a PC card.

Since, basically, a PC card inserted into a notebook PC is owned by auser of a notebook PC, no problem will arise even if a PC card securitymechanism interacts with the security mechanism for the main body of thenotebook PC. This is rather convenient for the user. In actuality,however, when a PC card is inserted in the docking station, nodetermination is made as to whether it is owned by a single user or bymultiple users, and the security policy varies in each case. Therefore,the security for a PC card is accompanied by the same problems as is thesecurity for the docking station. If the PC card security mechanism isspecifically designed for either a single user mode or a multi-usermode, the security of one of them can not be ensured. In addition, if aspecial locking mechanism is provided for each mode, the operation willbecome complex.

Docking station “Dock,/SelectaDock” (previously described), which isproduced by IBM Corp. for the notebook PC “IBM ThinkPad760” sold by IBMJapan Ltd., has PC card slots, and permits the separate locking of PCcard slots in the notebook PC and in the docking station, so that thedifference between the security policies for the single user mode andthe multi-user mode can be absorbed. As is described above, however, itis required that two security mechanisms be used, so that a user must beaccountable for two different keys.

The prevention of the theft of a PC card from an expansion unit is notcited in previously described Japanese Unexamined Patent PublicationsNo. Hei 06-124141 and No. Hei 07-104884.

It is, therefore, one object of the present invention to provide asuperior docking unit for a portable computer that can effectivelyprevent the theft of the main body of the docking unit and a portablecomputer mounted thereon.

It is another object of the present invention to provide a superiordocking unit for a portable computer that can provide adequate theftprevention environments for both a “single user mode”, during which thedocking unit is used by only one user, and a “multi-user mode”, duringwhich the docking unit is shared by a plurality of users.

It is an additional object of the present invention to provide asuperior docking unit for a portable computer that can adequatelyprevent the theft of a portable computer mounted on the docking unit,which is either in a “single user mode” during which the docking unit isused by only one user or a “multi-user mode” during which the dockingunit is shared by a plurality of users.

It is a further object of the present invention to provide a superiordocking unit for a portable computer that permits the exchange of aportable computer mounted thereon, while ensuring the security of thedocking unit and a PC card.

It is still another object of the present invention to provide asuperior docking unit for a portable computer that can adequatelyprevent the theft of a PC card in both a “single user mode” during whichthe docking unit is used by only one user, and a “multi-user mode”during which the docking unit is shared by a plurality of users.

SUMMARY OF THE PRESENT INVENTION

To achieve the above objects, according to a first aspect of the presentinvention, a docking unit for mounting a portable computer comprises:(a) a main body; (b) a mounting portion for mounting a portablecomputer; (c) a first locking portion provided on the outer wall of themain body; (d) a second locking portion provided on the outer wall ofthe main body; (e) engaging means for engaging with the portablecomputer mounted on the mounting portion; and (f) engaging control meansfor controlling the engaging means from being released in response to acondition where a locking member, for securing the docking unit to adesired surrounding object, is loaded either at the first lockingportion or at the second locking portion.

According to a second aspect of the present invention, a docking unitfor mounting a portable computer comprises: (a) a main body; (b) amounting portion for mounting a portable computer; (c) a firstkensington slot provided on the outer wall of the main body; (d) asecond kensington slot provided on the outer wall of the main body; (e)engaging means for engaging with the portable computer mounted on themounting portion; and (f) engaging control means for controlling theengaging means from being released in response to whether a kensingtonlock is inserted into the first kensington slot or the second kensingtonslot.

According to a third aspect of the present invention, a docking unit formounting a portable computer comprises: (a) a main body; (b) a mountingportion for mounting a portable computer; (c) a first kensington slotprovided on the outer wall of the main body; (d) a second kensingtonslot provided on the outer wall of the main body; (e) engaging means forengaging with the portable computer mounted on the mounting portion; and(f) engaging control means for inhibiting the engaging means from beingreleased when a kensington lock is inserted into the first kensingtonslot, and for not inhibiting the engaging means from being released whenthe kensington lock is inserted into the second kensington slot.

According to a fourth aspect of the present invention, a docking unitfor mounting a portable computer comprises: (a) a main body; (b) amounting portion for mounting a portable computer; (c) a PC card slotprovided in the main body for inserting a PC card; (d) ejecting meansprovided for the PC card slot for ejecting an inserted PC card; (e) afirst kensington slot provided on the outer wall of the main body; (f) asecond kensington slot provided on the outer wall of the main body; (g)engaging means for engaging with the portable computer mounted on themounting portion; and (h) engaging control means for inhibiting bothactivation of the ejecting means and release of the engaging means whena kensington lock is inserted into the first kensington slot, and forinhibiting activation of the ejecting means but not inhibiting releaseof the engaging means when the kensington lock is inserted into thesecond kensington slot.

According to a fifth aspect of the present invention, a docking unit formounting a portable computer comprises: (a) a main body; (b) a mountingportion for mounting a portable computer; (c) a first kensington slotprovided on the outer wall of the main body; (d) a second kensingtonslot provided on the outer wall of the main body; (e) engaging means forengaging with the portable computer mounted on the mounting portion; (f)engaging release means for releasing the portable computer from anengaging with the engaging means; and (g) notification means forinhibiting release of an engaging by notifying the engaging releasemeans that a kensington lock has been inserted into the first kensingtonslot, and for not notifying the engaging release means that thekensington lock has been inserted into the second kensington slot.

According to a sixth aspect of the present invention, a docking unit formounting a portable computer comprises: (a) a main body; (b) a mountingportion for mounting a portable computer; (c) a PC card slot provided inthe main body for inserting a PC card; (d) restricting means formed atthe ejection opening of the PC card slot to restrict the exchange of aPC card; (e) a first locking portion provided on the outer wall of themain body; (f) a second locking portion provided on the outer wall ofthe main body; (g) restricting release means for releasing a restrictionof the exchange of a PC card imposed by the restricting means; and (h)means for maintaining a restriction condition of the exchange of a PCcard in response to whether a locking member, for securing the dockingunit to a desired peripheral object, is attached to the first lockingportion or the second locking portion.

According to a seventh aspect of the present invention, a docking unitfor mounting a portable computer comprises: (a) a main body; (b) amounting portion for mounting a portable computer; (c) a PC card slotprovided in the main body for inserting a PC card; (d) restricting meansformed at the ejection opening of the PC card slot to restrict theexchange of a PC card; (e) a first kensington slot provided on the outerwall of the main body; (f) a second kensington slot provided on theouter wall of the main body; (g) restricting release means for releasinga restriction of the exchange of a PC card imposed by the restrictingmeans; and (h) notification means for notifying the restricting releasemeans whether a kensington lock has been inserted into the first or thesecond kensington slot, in order to maintain the restriction conditionof the exchange of a PC card.

According to an eighth aspect of the present invention, a docking unitfor mounting a portable computer comprises: (a) a main body; (b) amounting portion for mounting a portable computer; (c) a PC card slotprovided in the main body for inserting a PC card; (d) restricting meansformed at the ejection opening of the PC card slot to restrict theexchange of a PC card; (e) a first kensington slot provided on the outerwall of the main body, (f) a second kensington slot provided on theouter wall of the main body; (g) engaging means for engaging with theportable computer mounted on the mounting portion; (h) engaging releasemeans for releasing the portable computer from an engaging with theengaging means; (i) restricting release means for releasing arestriction of the exchange of a PC card imposed by the restrictingmeans; (j) first notification means for inhibiting release of anengagement by notifying the engaging release means that a kensingtonlock has been inserted into the first kensington slot, and for notnotifying the engaging release means that the kensington lock has beeninserted into the second kensington slot; and (k) second notificationmeans for maintaining restriction of the exchange of a PC card bynotifying the restricting release means that the kensington lock hasbeen inserted into either the first or the second kensington slot.

According to a ninth aspect of the present invention, a docking unit formounting a portable computer comprises: (a) a main body; (b) a mountingportion for mounting a portable computer; (c) a PC card slot provided inthe main body for inserting a PC card; (d) ejecting means provided forthe PC card slot for ejecting an inserted PC card; (e) a firstkensington slot provided on the outer wall of the main body; (f) asecond kensington slot provided on the outer wall of the main body; (g)engaging means for engaging with the portable computer mounted on themounting portion; and (h) engaging control means for inhibiting both anejection of the ejecting means and release of the engaging means when akensington lock is inserted into the first kensington slot, and for notinhibiting neither an ejection of the ejecting means nor release of theengaging means even though the kensington lock is inserted into thesecond kensington slot.

According to a tenth aspect of the present invention, a docking unit formounting a portable computer comprises: (a) a main body; (b) a mountingportion for mounting a portable computer; (c) a PC card slot provided inthe main body for inserting a PC card; (d) restricting means formed atthe ejection opening of the PC card slot to restrict the exchange of aPC card; (e) a first kensington slot provided on the outer wall of themain body; (f) a second kensington slot provided on the outer wall ofthe main body; (g) restricting release means for releasing a restrictionof the exchange of a PC card imposed by the restricting means; and (h)notification means for inhibiting release of a restriction by notifyingthe restricting release means that a kensington lock has been insertedinto the first kensington slot, and for not notifying the restrictingrelease means that the kensington lock has been inserted into the secondkensington slot.

According to an eleventh aspect of the present invention, a docking unitfor mounting a portable computer comprises: (a) a main body; (b) amounting portion for mounting a portable computer; (c) a PC card slotprovided in the main body for inserting a PC card; (d) restricting meansformed at the ejection opening of the PC card slot to restrict theexchange of a PC card; (e) a first kensington slot provided on the outerwall of the main body; (f) a second kensington slot provided on theouter wall of the main body; (g) engaging means for engaging with theportable computer mounted on the mounting portion; (h) engaging releasemeans for releasing the portable computer from engaging with theengaging means; (i) restricting release means for releasing arestriction of the exchange of a PC card imposed by the restrictingmeans; (j) first notification means for inhibiting release of anengagement by notifying the engaging release means that a kensingtonlock has been inserted into the first kensington slot, and for notnotifying the engaging release means that the kensington lock has beeninserted into the second kensington slot; and (k) second notificationmeans for inhibiting release of an engagement by notifying the engagingrelease means that a kensington lock has been inserted into the firstkensington slot, and for not notifying the engaging release means thatthe kensington lock has been inserted into the second kensington slot.

According to a twelfth aspect of the present invention, a portableelectronic apparatus comprises: (a) a main body; (b) a first lockingportion provided on the outer wall of the main body; (c) a secondlocking portion provided on the outer wall of the main body; (d) firsttheft prevention means for setting the main body to a first securitymode when a locking member, for locking the main body to a desiredperipheral object, is inserted into the first locking portion; and (e)second theft prevention means for setting the main body to a secondsecurity mode which differs from the first security mode, when thelocking member is inserted into the second locking portion.

According to a thirteenth aspect of the present invention, a portableelectronic apparatus comprises: (a) a main body; (b) a first kensingtonslot provided on the outer wall of the main body; (c) a secondkensington slot provided on the outer wall of the main body; (d) firsttheft prevention means for setting the main body to a first securitymode when a kensington lock is inserted into the first kensington slot;and (e) second theft prevention means for setting the main body to asecond security mode being different from the first security mode, whenthe kensington lock is inserted into the second kensington slot.

According to a fourteenth aspect of the present invention, a dockingunit for mounting a portable computer comprises: (a) a main body; (b) amounting portion, for mounting a portable computer thereon; (c) adocking connector provided at an elevated location on the mountingportion for an electrical connection with the portable computer on themounting portion; (d) engaging means for engaging with the portablecomputer mounted on the mounting portion; (e) ejecting means, providedon the mounting portion, that can be vertically projected and retracted,and that is vertically projected and raises the portable computermounted on the mounting portion, so that the portable computer can beremoved from the docking connector; (f) ejecting instruction means usedby a user to instruct ejection of the mounted portable computer; (g)notification means for, in response to a user's operation of theejecting instruction means, releasing the engaging means and extendingthe ejecting means upward; and (h) retracting prevention means for, evenafter the user has operated the ejecting instruction means, preventingthe ejecting means when elevated from descending and being retractedinto the mounting portion.

In a docking unit for a portable computer according to the fourteenthaspect of the present invention, for preventing retraction, sufficientdriving force shall be provided for the restricting prevention means tocounter the portable computer's weight. A docking unit for a portablecomputer according to the present invention has the first and the secondkensington slots positioned on the outer wall of the main body.

When the kensington lock is inserted into the first kensington slot,this event is transmitted to inhibit the release of the engaging of themounted portable computer, and to unenable its removal. But when thekensington lock is inserted into the second kensington slot, this eventis not transmitted, so that the mounted portable computer can beremoved. Therefore, in the single user mode, when the kensington lock isinserted into the first kensington slot, the portable computer and thedocking unit can be secured together. In the multi-user mode, when thekensington lock is inserted into the second kensington slot, only thedocking unit is secured, and the attachment and removal of the portablecomputer is ensured. In other words, the docking unit for a portablecomputer of the present invention can absorb the differences in thesecurity policies for the single user mode and the multi-user mode.

In the docking unit according to the fourth, seventh and eighth aspects,when the kensington lock is inserted into either the first or the secondkensington slots, this event is transmitted to restrict the exchange ofa PC card relative to the docking unit. Not only the main body of thedocking unit and the mounted notebook PC, but also the PC card arelocked, so that the theft of PC cards can be prevented.

In the docking unit according to the ninth, tenth and eleventh aspects,when the kensington lock is inserted into the first kensington slot,this event is transmitted to restrict the exchange of a PC card relativeto the docking unit. When the kensington lock is inserted into thesecond kensington slot, this event is not transmitted, and therestriction concerning the exchange of the PC card relative to thedocking unit is freely released. Therefore, in the single user mode, theexchange of the PC card relative to the docking unit is inhibited byinserting the kensington lock into the first kensington slot, and theftof both the PC card and the docking unit can be prevented. But in themulti-user mode, the exchange of a PC card relative to the docking unitis ensured by the insertion of the kensington lock into the secondkensington slot, and PC cards can be exchanged by the individual users.

That is, according to the docking unit of the present invention,environments that provide adequate safeguards for the prevention oftheft are provided for the “single user mode”, in which the docking unitis used by only one user, and the “multi-user mode”, in which thedocking unit is shared by a plurality of users. Further, the dockingunit of the present invention can handle the respective securitypolicies for PC cards that differ for the single user mode and for themulti-user mode.

With the docking unit for a portable computer of the present invention,the theft of PC cards can be effectively prevented in the environmentfor the “single user mode”, in which the docking unit is employed byonly a single user and in that for the “multi-user mode”, in which thedocking unit is employed by a plurality of users.

In the docking unit according to the fourteenth aspect, there is littlechance that the notebook PC that is ejected upward will be dropped andthat the connectors will come into contact. Thus, the chattering thataccompanies the contact of the connectors and the damage to data that isdue to the chattering can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

The other objects, features, and advantages of the present inventionwill become apparent in due course during the detailed description ofthe embodiment of the present invention, which will be given whilereferring to the accompanying drawings.

FIG. 1 is a diagram illustrating outlines of a docking station 10 and anotebook PC 50.

FIG. 2 is a perspective view of the rear face of the docking station 10.

FIG. 3 is a diagram illustrating the internal structure of the dockingstation 10, with the edges of a case being represented by broken lines.

FIG. 4 is a cross-sectional view of the docking station 10 showing themovement of a slider 41 correlated with the attachment and removal ofthe notebook PC 50.

FIG. 5 is another cross-sectional view of the docking station 10.

FIG. 6 is the same cross-sectional view as in FIG. 5 for the dockingstation 10, and more specifically, shows the condition where a stopperplate 46 obstructs the movement of a link 47 when a kensington lock isinserted.

FIG. 7 is a diagram illustrating the internal structure of the dockingstation 10, with the edges of the case being represented by brokenlines, and more specifically shows the movement of card shutters 23 aand 23 b.

FIG. 8 is a diagram for explaining a second embodiment of the presentinvention.

FIG. 9 is a diagram for explaining a third embodiment of the presentinvention, and more specifically, is a diagram illustrating the internalstructure of the docking station 10.

FIG. 10 is a diagram for explaining the third embodiment, and morespecifically, it is a side view of the docking station 10.

FIG. 11 is a diagram illustrating a specific style of notebook PC 100and docking station 200.

FIG. 12 is a diagram showing the condition where a notebook PC is lockedby using a kensington lock.

FIG. 13 is a schematic diagram illustrating the assembly of a kensingtonlock, and more specifically, with FIG. 13(a) being an exploded diagramfor the kensington lock, FIG. 13(b) being a diagram for the assemblingof a kensington lock, and FIGS. 13(c),(d) and (e) being diagrams forcomparing the size and shape of the kensington slot with the those ofthe head of a T-shaped shaft, contact members, etc.

FIG. 14 is a diagram illustrating the condition where the kensingtonlock is inserted into the outer wall of the PC, and more specificallywith FIG. 14(a) being a side view and FIG. 14(b) being a diagram for thekensington slot viewed from the inside of the PC.

FIG. 15 is a diagram illustrating the condition where the kensingtonlock is fixed to the outer wall of the PC, and more specifically, FIG.15(a) being a side view and FIG. 15(b) being a diagram for thekensington slot viewed from the inside of the PC.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

FIG. 1 is a diagram illustrating the outline of a docking station 10 anda notebook PC 50 according to the present invention. The docking station10 has a relatively thick main body and a thin mounting portion 14provided at the front of the main body.

A pair of kensington slots 11 and 12 are formed in a right side wall ofthe main body of the docking station 10. The kensington slots 11 and 12,which are the same size, can accept a T-shaped shaft of a kensingtonlock (previously described and not shown in FIG. 1). The prevention ofthe theft of the docking station 10 can be ensured by inserting akensington lock into at least one of the kensington slots 11 and 12.

An eject button 13 and a slide knob 17 are provided on the top face ofthe main body. The eject button 13 is used to disengage the mountednotebook PC 50 from the docking station 10 when the notebook PC 50 is tobe removed. When the eject button 13 is pressed, this action istransmitted to front hooks 15 a, 15 b, 15 c and 15 d, which will bedescribed later. The slide knob 17 is so provided that it slides forwardand backward along an opening formed in the top face of the main body.The movement of the slide knob 17 is transmitted to a mechanism forinhibiting the exchange of a PC card, which will be described later.

The mounting portion 14 is a table on which the notebook PC 50 ismounted. The hooks 15 a, 15 b, 15 c and 15 d are provided at the fourcorners of the mounting portion 14. The hooks 15 have an L-shaped head,a corner of which is chamfered, and can move 5 mm forward and backward.To mount the notebook PC 50, first, the heads of the-hooks 15 a, 15 b,15 c and 15 d are inserted into engagement holes 55 a, 55 b, 55 c and 55d, which are formed in the bottom of the notebook PC 50. Then, theL-shaped heads of the hooks 15 engage the bottom of the notebook PC 50,so that the units 10 and 50 are joined together. To remove the notebookPC 50 from the docking unit 10, the eject button 13 is pressed torelease the hooks 15 and more than 5 mm forward, so that they aredisengaged from the notebook PC 50, which will be described later. Thenumber of hooks 15 is a design matter determined in accordance with thestrength required to secure the notebook PC 50. Even if only one hook isprovided on each side, instead of two hooks as in the embodiment, thishas no affect on the subject of the present invention.

A docking connector 16 is provided facing upward for electric connectionwith the notebook PC 50. A docking connector 56, whose specificationsmatch those of the connector 16, is provided facing downward at acorresponding location in the bottom of the notebook PC 50. When thenotebook PC 50 is mounted on the mounting portion 14, the dockingconnectors 16 and 56 are coupled together to permit the exchange ofelectric signals between the units 10 and 50. Although, in thisembodiment, the docking connecters 16 and 56 are constituted by twoconnector rows, this is a design matter determined in accordance withthe number of pins that are provided for the connectors 16 and 56. Thesize and the structure of the connectors 16 and 56 do not directlyaffect the subject of the present invention.

The top face of the mounting portion 14 is moderately inclined to thefront, so that the keyboard unit of the mounted notebook PC 50 is tiltedto facilitate typing.

The notebook PC 50 in FIG. 1 has a so-called “clam shell” structureconstituted by a main body which includes a keyboard unit (not shown),and a lid which includes a liquid crystal display (not shown). Insidethe case of the notebook PC 50 are provided a system board on which aremounted various electronic components, such as a CPU, a memory and avideo controller chip; and peripheral devices, such as a hard disk drive(HDD) and a floppy disk drive (FDD). The structures and operations ofthese electric/electronic components are not directly related to thesubject of the present invention, so that no further explanation forthem will be given in this specification.

FIG. 2 is a diagram illustrating the rear face of the docking station10. A portion 20 that is raised to the rear is formed on the rear face.

A pair of PC card slots 21 a and 21 b are mounted in the raised portion20. Type- cards that conform to the standard developed by PCMCIA(Personal Computer Memory Card International Association)/JEIDA (JapanElectronic Industry Development Association) can be inserted into bothof the slots 21 a or 21 b. A pair of eject buttons 22 a and 22 b areprovided at either end of the raised portion 20 to eject inserted PCcards (not shown). The PC card ejecting mechanism is not directlyrelated to the subject of the present invention, so that no furtherexplanation for it will be given.

A pair of horizontally retractable card shutters 23 a and 23 b(indicated by the broken lines in FIG. 2) are attached in almost thecenter of the raised portion 20. The movement of the card shutters 23 aand 23 b interacts with the sliding of the slide knob 17 (previouslydescribed). In other words, when the slide knob 17 is moved to the frontof the docking station 10, this movement is transmitted by an internalmechanism (which will be described later) to the card shutters 23 a and23 b, and they are moved to the right and to the left respectively.Since when the card shutters 23 a and 23 b appear they cover at leastpart of the exchange opening of each of the card slots 21 a and 21 b,the exchange of PC cards can be inhibited. As a result, the theft, suchas the stealing of an inserted PC card, or the insertion of a PC card byan unauthorized user who wants to access internal data in the units 10and 50 via the PC card, can be prevented. Although the docking station10 in this embodiment has two PC card slots, the number of card slotsprovided is merely a design matter.

On the other portions of the rear face of the docking station 10 areprovided an external mouse port 24, an external keyboard port 25, a MIDI(Musical Instrument Digital Interface)/joystick port, a parallel port27, a serial port 28, an external FDD port 29, an external CRT (CathodeRay Tube) port 30, and a line input/output port 31. For example, a modemcan be connected to the serial port 28, and a printer can be connectedto the parallel port 27. Port signals assigned to the connector pins ofthe docking connector 16 are transmitted within the docking station 10and relayed to the corresponding ports. The types of ports and thenumber of ports provided for the docking station 10 are design mattersand are not directly related to the subject of the present invention.

The internal structure of the docking station 10 and the operationalcharacteristics of its movable portion will now be described in detail.

In FIG. 3 is shown the internal structure of the case of the dockingstation 10, which is described by chain double-dashed lines. To avoidcomplexity in the drawing, components that are not related to thesecurity mechanism are not shown. Peripheral members for supportingmovable portions, or for defining the directions of their movements, arein actuality provided, but are not shown in order to simplify thedrawing.

A slider 41 has an elongated leg extending to the front, with two hooks15 a and 15 b integrally formed at and near the end of the leg, and theprotrusion 42 integrally formed at its center. The hooks 15 a and 15 bextend outward through openings formed in the upper face of the mountingportion 14. A first linear hole 43 and a second linear hole 44 areformed at the rear in the slider 41. The linear holes 43 and 44 arelocated at positions that correspond to those of the kensington slots 11and 12, which are formed on the right side wall of the docking station10. Since the widths of the linear holes 43 and 44 are the same as thewidth of the head of the T-shaped shaft of a kensington slot, the headof the T-shaped shaft inserted in either slot 11 or 12 can pass througheither the hole 43 or 44. It should be noted that the length of thefirst linear hole 43 is the same as the head of the T-shaped shaft,while the second linear hole 44 is longer than the head of the T-shapedshaft.

The slider 41 is so supported by a member (not shown) that it can slideforward and backward. When no kensington lock is inserted into eitherkensington slot 11 or 12, the slider 41 can move forward. When akensington lock is inserted into the kensington slot 12, thecorresponding linear hole 44 has a larger clearance in the forward andbackward direction, and the forward movement of the slider 41 is thuspermitted. When a kensington lock is inserted into the kensington slot11, the corresponding linear hole 43 has almost no clearance in theforward and backward direction, and the forward movement of the slider41 is thus inhibited.

One end of a coil spring 45 is fixed to the rear portion of the slider41, and the other end is fixed to the rear wall (not shown) of thedocking station 10. The slider 41 is constantly retracted by therecovery force exerted by the coil spring 45.

FIG. 4 is a cross-sectional view of the docking station 10. Thecondition where the slider 41 slides is shown correlated with theattachment and the removal of the notebook PC 50.

The attachment of the notebook PC 50 will now be explained. The hooks 15a and 15 b have L-shaped heads, one corner of which is chamfered. Theengagement holes 55 a and 55 b, which are formed in the bottom of thenotebook PC 50, have the same internal size as the external size of theheads of the hooks 15 a and 15 b, and their front edges are located 5 mmforward of the hooks 15 a and 15 b. To mount the notebook PC 50,therefore, first, the heads of the hooks 15 a and 15 b contact the rearedges of the engagement holes 55 a and 55 b. As the bottom face of thenotebook PC 50 descends, the rear edges of the engagement holes 55 a and55 b slide along the chamfered portions of the heads of the hooks 15 aand 15 b, and the hooks 15 a and 15 b are driven forward. Accordingly,the slider 41, which is integrally formed with the hooks 15 a and 15 b,is also moved forward against the recovery force exerted by the coilspring 45 (see the broken line in FIG. 4). When the heads of the hooks15 a and 15 b are fully inserted through the bottom of the notebook PC50, the hooks 15 a and 15 b and the slider 41, for which obstacles totheir rearward movement no longer exist, are returned to their initialpositions. When the L-shaped heads of the hooks 15 a and 15 b contactthe rear edges of the engagement holes 55 a and 55 b, the units 10 and50 are fully engaged.

The removal of the notebook PC 50 will now be explained. The bottom ofthe eject button 13, which is cut off diagonally, contacts the distalend of the linear protrusion 42, which is integrally formed with theslider 41. Thus, when the eject button 13 is pressed down, the linearprotrusion 42 is forced forward and slides along the inclined surface ofthe bottom of the eject button 13 (see the broken line in FIG. 4). As aresult, the slider 41 and the hooks 15 a and 15 b, which are integrallyformed with the linear protrusion 42, are driven forward against therecovery force exerted by the coil spring 45. Then, the point is reachedwhere the bottom wall of the notebook PC 50, which is engaged by thehooks 15 a and 15 b that pass through the engagement holes 55 a and 55b, is released, so that the notebook PC 50 can be removed.

When no kensington lock is inserted into either kensington slot 11 or12, the forward movement of the slider 41 is not restricted, and themounted notebook PC 50 can be freely removed. Even when a kensingtonlock is inserted into the kensington slot 12, the slider 41 can moveforward, permitting the mounted notebook PC 50 to be removed, andensuring the implementation of the multi-user mode (the environmentwherein the notebook PCs of a plurality of users can be employed). Onthe other hand, when a kensington lock is inserted into the kensingtonslot 11, the slider 41 can not move forward and the eject button 13 cannot be depressed, so that the hooks 15 a, 15 b, 15 c and 15 d can not bereleased from the engagement holes 55 a, 55 b, 55 c and 55 d. As aresult, since the removal of the notebook PC 50 is inhibited and thedocking station 10 and the notebook PC 50 are securely held together,the physical security inherent to the single user mode is provided.

Although not shown, the slider 41 and the coil spring 45 aresymmetrically depicted also on the left side of the docking station 10.The depression of the eject button 13 is also transmitted to the slider41 on the left side by a transmission mechanism (not shown). It shouldbe noted that since no kensington slots are formed in the left side wallof the docking station 10, liner holes 43 and 44 are not required forthe left slider 41.

Referring back to FIG. 3, a stopper plate 46 is a bent member, andshafts 46 a and 46 b project outward from the ends at the curvedportion. These shafts 46 a and 46 b are supported by a support member(not shown) and rotate in the directions indicated by an arrow A.

FIGS. 5 and 6 are cross sectional views of another docking station 10.The positional relationship of the stopper plate 46 and the slider 41should be understood. The stopper plate 46 is located inside the slider41. When the kensington lock is inserted into either the kensington slot11 or 12, the head of the T-shaped shaft passes through either linearhole 43 or 44 of the slider 41, and contacts the side portion of thestopper plate 46, which is then rotated clockwise in FIG. 6 (in adirection indicated by an arrow A). As a result, the upper face of thestopper plate 46 is elevated from its initial horizontal position.

Referring again to FIG. 3, a link 47 is a thin plate in an arrowheadshape. Its distal end is supported at the upper wall of the docking,station 10 by a shaft 48 so that it can be rotated in the directionindicated by an arrow C. The previously described slide knob 17 isintegrally formed with the upper face of the link 47. The slide knob 17is exposed from above and extends upward into a rectangular opening thatis formed on the upper face of the docking station 10, and can be slidin the longitudinal direction of the opening, i.e., in the directionindicated by an arrow B. When the slide knob 17 is slid to the rear, thelink 47 is moved in the direction indicated by the arrow C.

The leg of the link 47 extends over to the right side of the main bodyof the docking station 10. When a kensington lock has been inserted intoeither the kensington slot 11 or 12, and the stopper plate 46 is rotatedin the direction indicated by the arrow A, the movement of the leg ofthe link 47 is obstructed by the upper face of the stopper plate 46 (seeFIG. 6), and forward movement of the link 47 and the slide knob 17 isinhibited.

The card shutter 23 is formed below the link 47. The card shutter 23 isa U-shaped metal plate, the center portion 23′ of which is fixed to theupper wall of the docking station 10. Portions 23 a and 23 b, which arebent outward from the U-shape, are formed at the ends of the legs of theU-shaped card shutter 23. As is explained while referring to FIG. 2, thebent portions 23 a and 23 b are used to cover the exchange openings ofthe PC card slots 21 a and 21 b.

A pair of bent portions extend outward from the upper edge in the centerof the legs of the card shutter 23. Linear cam slits 49 a and 49 b areformed in the respective bent portions and approach each other as theygo to the rear. A pair of small protrusions 47 a and 47 b, which areformed on the lower face of the link 47, engage the cam slits 49 a and49 b. Since the gap between the small protrusions 47 a and 47 b isconstant, the cam slits 49 a and 49 b are forced to maintain the samegap in accordance with the location to which the slide knob 17, i.e.,the link 47, is moved forward and backward.

When the slide knob 17 is moved to the frontmost position, and the smallprotrusions 47 a and 47 b, which engage the cam slits 49 a and 49 b isthe greatest, as is shown in FIG. 3, the U-shaped legs of the cardshutter 23 are closed. As a result, the bent portions 23 a and 23 bapproach the center, the exchange openings of the PC card slots 21 a and21 b are fully opened, and the exchange of PC cards can be performed. Inshort, the movement of the slide knob 17 to the front permits thedeactivation of the physical security for the PC card slots 21 a and 21b.

When the slide knob 17 is moved to the rearmost position, and the smallprotrusions 47 a and 47 b, which engage the cam slits 49 a and 49 b,reach the point where the gap between the cam slits 49 a and 49 b is thesmallest, as is shown in FIG. 7, the U-shaped legs of the card shutter23 are opened. As a result, the bent portions 23 a and 23 b appear andcover at least part of the exchange openings for the PC card slots 21 aand 21 b, and the exchange of the PC cards is inhibited. The theft of aninserted PC card in the slot 21 a or 21 b by extracting it withoutpermission, or the insertion of a PC card by an unauthorized user toaccess information available in the units 10 and 50, can be prevented.In short, the rearward movement of the slide knob 17 permits theactivation of the physical security for the PC card slots 21 a and 21 b.

From the point of view of the physical security, preferably, the cardshutter 23 is made of relatively hard material, such as carbon steel,that is difficult to deform.

The security mechanism in the first embodiment will now be described. Aswas previously described, the docking station 10 has the two kensingtonslots 11 and 12.

(1) When the Kensington Lock is Inserted into the Kensington Slot 11

The docking station 10 is secured at a predetermined position in anoffice, and its physical security is ensured. Since the operation of theeject button 13 is disabled, and the hooks 15 a, 15 b, 15 c and 15 d cannot be released from the engagement holes 55 a, 55 b, 55 c and 55 d, themounted notebook PC 50 is securely held to the docking station 10. Thatis, the physical security inherent to the single user mode, during whichonly one user employs the docking station 10, is provided.

In this condition, the link 47 is temporarily moved to the rear, inaccordance with the movement of the slide knob 17, and can not bereturned to the front because its movement is obstructed by the stopperplate 46 (see FIG. 6). Thus, the bent portions 23 a and 23 b of the cardshutter 23 are exposed, and the exchange of PC cards is inhibited.

(2) When the Kensington Lock is Inserted into the Kensington Slot 12

The docking station 10 is secured at a predetermined location in anoffice, and its physical security is ensured. Since the operation of theeject button 13 is enabled, the mounted notebook PC 50 can be removedfrom the docking station 10 and can be replaced with another notebookPC. In other words, the physical security inherent to the multi-usermode, during which a plurality of PC users share the docking station 10,is provided.

In this condition, the link 47 is temporarily moved to the rear, inaccordance with the movement of the slide knob 17, and can not bereturned to the front because its movement is obstructed by the stopperplate 46 (see FIG. 6) Thus, the bent portions 23 a and 23 b of the cardshutter 23 are exposed, and the exchange of PC cards is inhibited.

Second Embodiment

The difference between the first and the second embodiments is that thedefinition of the physical security provided in the multi-user mode isdifferent.

FIG. 8 is a diagram illustrating the internal structure of a dockingstation 10 according to a second embodiment of the present invention.The arrangement in FIG. 8 differs from that in FIG. 7 in that a linearslit 46 a is formed in a stopper plate 46. The linear slit 46 a is soformed that it has the same shape and size as the first kensington slot11 at a position corresponding to the second kensington slot 12.

When a kensington lock is inserted into the second kensington slot 12,the head of the T-shaped shaft of the kensington lock passes not onlythrough a second linear slit 44, but also through the linear slit 46 a,and a stopper plate 46 is not rotated in the direction indicated by thearrow A in FIG. 6. Therefore, in this condition, the release of the cardshutter 23 is permitted.

More specifically, when a kensington lock is inserted into thekensington slot 12, the exchange of notebook PCs and the exchange of PCcards are still enabled though the docking station 10 is secured at apredetermined location in an office. That is, the multi-user mode in thesecond embodiment permits the shared use of the PC card slots 21 of thedocking station 10.

When the kensington lock is inserted into the first kensington slot 11,the same physical security as that provided in the first embodiment isenabled. In other words, the docking station 10, the notebook PC 50, andthe PC card slot 21 are locked, and this arrangement is used by a singleuser.

Third Embodiment

The feature of a third embodiment is not a security mechanism, i.e., alocking mechanism, but an ejecting mechanism for a mounted notebook PC.The locking mechanism in this embodiment is equivalent to that in thefirst or the second embodiment, so that no detailed explanation of itwill be given.

FIG. 9 is a diagram illustrating the internal structure of a dockingstation 10 according to the third embodiment. The locking mechanism,i.e., the structures of a slider 41, a stopper plate 46, a link 47 and acard shutter 23, and its operational characteristics are the same asthose for corresponding components in the first embodiment.

When an eject button 13 (not shown in FIG. 9) provided on the upper faceof the docking station 10 is depressed, a force exerted in the directionindicated by an arrow P is applied to a cam 62.

The cam 62 is fixed to one end of a link bar 61 that is supportedrotatably. When a kensington lock is not inserted into either slot 11 or12, depression force P applied to the eject button 13 is changed to arotational force for rotating the link bar 61 in the direction indicatedby an arrow Q. A pair of cams 63 a and 63 b are integrally formed ateither end of the link bar 61. The rotation force Q is transmittedequally to both sides by the link bar 61 and to the cams 63 a and 63 b.

Each of the cams 63 a and 63 b has a bent portion at its distal end.When the cams 63 a and 63 b are driven in the direction indicated by thearrow Q, these bent portions are brought into contact with the ends ofejectors 64 a and 64 b.

The ejectors 64 a and 64 b are U-shaped products that have a protrusionon either end. A pair of shafts are projected to either side at thecenter of each of the ejectors 64 a and 64 b. These shafts are supportedrotatably by a support member (not shown). The protrusions on the endsof the ejectors 64 a and 64 b contact the bent portions of the cams 63 aand 63 b, as was previously described. The protrusions on the other endsproject upward through openings formed in a mounting portion 14, so thatthe protrusions can be projected and retracted. When the eject button 13is depressed, the rotational force exerted in the direction indicated byan arrow R is applied to the ejectors 64 a and 64 b. As a result, theprotrusions on the opposite ends of the ejectors 64 a and 64 b areprojected outward, and push against the bottom face of the mountednotebook PC 50, which is then disengaged from the connectors 16 andejected.

When the depression of the eject button 13 is halted, the rotationalforce R received from the cams 63 a and 63 b is removed. In thisembodiment, however, since the lower portion at the other ends of theejectors 64 a and 64 b are supported by leaf springs 65 a and 65 b, therotational force R for the ejectors 64 a and 64 b is maintained to adegree. Thus, the ejected notebook PC is prevented from dropping back onto the mounting portion 14 (see FIG. 10).

As is shown in FIG. 11, when the notebook PC is horizontally attached toor detached from the docking station, the notebook PC, after it isejected, remains at the position on the mounting surface at which it wasejected. However, if, as in this embodiment, the notebook PC isvertically attached to and detached from the docking station, and thedocking connector 16 is provided facing upward, after the notebook PC isejected its own weight may cause it to drop down and produce an unstableelectrical contact condition between the connectors. According to thethird embodiment, since the ejectors 64 a and 64 b are supported by theleaf springs 65 a and 65 b, and the notebook PC can not easily fall, thedocking connectors, once separated from each other will not erroneouslybe brought into contact. As a result, the chattering that accompaniesthe contact of the connectors, and the damage to data due to thechattering can be prevented.

The present invention has been described in detail while referring to aspecific embodiment. However, it should be obvious to one havingordinary skill in the art that various modifications or revisions of theembodiment are possible within the scope of the present invention. Thatis, although the present invention has been disclosed by using anexample, it should not be limited to that example. To fully understandthe subject of the present invention, the claims should be referred to.

As is described above, according to the present invention, provided is asuperior docking unit for a portable computer that can effectivelyprevent the theft of the main body of the docking unit and a portablecomputer mounted thereon.

Further, according to the present invention, provided is a superiordocking unit for a portable computer that can provide adequate theftprevention environments for a “single user mode” during which thedocking unit is used by only one user, and a “multi-user mode” duringwhich the docking unit is shared by a plurality of users.

In addition, according to the present invention, provided is a superiordocking unit for a portable computer that can adequately prevent thetheft of a portable computer mounted on the docking unit, which iseither in a “single user mode” during which the docking unit is used byonly one user or a “multi-user mode” during which the docking unit isshared by a plurality of users.

In addition, according to the present invention, provided is a superiordocking unit for a portable computer that permits the exchange of aportable computer mounted thereon, while ensuring the security of thedocking unit and a PC card.

Still further, according to the present invention, provided is asuperior docking unit for a portable computer that can adequatelyprevent the theft of a PC card in both a “single user mode”, duringwhich the docking unit is used by only one user, and a “multi-usermode”, during which the docking unit is shared by a plurality of users.

What is claimed is:
 1. A docking unit for mounting a portable computercomprising: (a) a main body; (b) a mounting portion for mounting aportable computer; (c) a first kensington slot provided on the outerwall of said main body; (d) a second kensington slot provided on theouter wall of said main body; (e) engaging means for engaging with theportable computer mounted on said mounting portion; (f) engaging releasemeans for releasing said portable computer from an engaging with saidengaging means; and (g) notification means for inhibiting release of anengaging by notifying said engaging release means that a kensington lockhas been inserted into said first kensington slot, and for not notifyingsaid engaging release means that said kensington lock has been insertedinto said second kensington slot.
 2. A docking unit for mounting aportable computer comprising: (a) a main body; (b) a mounting portionfor mounting a portable computer; (c) a PC card slot provided in saidmain body for inserting a PC card; (d) restricting means formed at theejection opening of said PC card slot to restrict the exchange of a PCcard; (e) a first kensington slot provided on the outer wall of saidmain body; (f) a second kensington slot provided on the outer wall ofsaid main body; (g) restricting release means for releasing arestriction of the exchange of a PC card imposed by said restrictingmeans; and (h) notification means for notifying said restricting releasemeans when a kensington lock has been inserted into one of said firstand said second kensington slots, in order to maintain said restrictioncondition of the exchange of a PC card.
 3. A docking unit for mounting aportable computer comprising: (a) a main body; (b) a mounting portionfor mounting a portable computer; (c) a PC card slot provided in saidmain body for inserting a PC card; (d) restricting means formed at theejection opening of said PC card slot to restrict the exchange of a PCcard; (e) a first kensington slot provided on the outer wall of saidmain body; (f) a second kensington slot provided on the outer wall ofsaid main body; (g) engaging means for engaging with the portablecomputer mounted on said mounting portion; (h) engaging release meansfor releasing said portable computer from an engaging with said engagingmeans; (i) restricting release means for releasing a restriction of theexchange of a PC card imposed by said restricting means; (j) firstnotification means for inhibiting release of an engagement by notifyingsaid engaging release means that a kensington lock has been insertedinto said first kensington slot, and for not notifying said engagingrelease means that said kensington lock has been inserted into saidsecond kensington slot; and (k) second notification means formaintaining restriction of the exchange of a PC card by notifying saidrestricting release means that said kensington lock has been insertedinto one of said first and said second kensington slots.
 4. A dockingunit for mounting a portable computer comprising: (a) a main body; (b) amounting portion for mounting a portable computer; (c) a PC card slotprovided in said main body for inserting a PC card; (d) restrictingmeans formed at said ejection opening of said PC card slot to restrictthe exchange of a PC card; (e) a first kensington slot provided on theouter wall of said main body; (f) a second kensington slot provided onthe outer wall of said main body; (g) restricting release means forreleasing a restriction of the exchange of a PC card imposed by saidrestricting means; and (h) notification means for inhibiting release ofa restriction by notifying said restricting release means that akensington lock has been inserted into said first kensington slot, andfor not notifying said restricting release means that said kensingtonlock has been inserted into said second kensington slot.
 5. A dockingunit for mounting a portable computer comprising: (a) a main body; (b) amounting portion for mounting a portable computer; (c) a PC card slotprovided in said main body for inserting a PC card; (d) restrictingmeans formed at said ejection opening of said PC card slot to restrictthe exchange of a PC card; (e) a first kensington slot provided on theouter wall of said main body; (f) a second kensington slot provided onthe outer wall of said main body; (g) engaging means for engaging withthe portable computer mounted on said mounting portion; (h) engagingrelease means for releasing said portable computer from an engaging withsaid engaging means; (i) restricting release means for releasing arestriction of the exchange of a PC card imposed by said restrictingmeans; (j) first notification means for inhibiting release of anengagement by notifying said engaging release means that a kensingtonlock has been inserted into said first kensington slot, and for notnotifying said engaging release means that said kensington lock has beeninserted into said second kensington slot; and (k) second notificationmeans for inhibiting release of an engagement by notifying said engagingrelease means that a kensington lock has been inserted into said firstkensington slot, and for not notifying said engaging release means thatsaid kensington lock has been inserted into said second kensington slot.6. A docking unit for mounting a portable computer comprising: (a) amain body; (b) a mounting portion, for mounting a portable computerthereon; (c) a docking connector provided at an elevated location onsaid mounting portion for an electrical connection with said portablecomputer on said mounting portion; (d) engaging means for engaging withsaid portable computer mounted on said mounting portion; (e) ejectingmeans, provided on said mounting portion, to be vertically projected andretracted, such that said ejecting means is vertically projected toraise said portable computer mounted on said mounting portion, forremoval from said docking connector; (f) ejecting instruction means usedby a user to instruct ejection of said mounted portable computer; (g)notification means for, in response to a user's operation of saidejecting instruction means, releasing said engaging means and extendingsaid ejecting means vertically upward; and (h) retracting preventionmeans for preventing said ejecting means when elevated from descendingand being retracted into said mounting portion.
 7. The docking unit fora portable computer according to claim 6, wherein said retractingprevention means includes means for preventing retraction against aweight of said portable computer.